FLOW CHARACTERISTICS OF UNDULAR HYDRAULIC JUMPS

Particle Image Velocity Measurements of Undular and Hydraulic Jumps

Measurements of the mean and turbulent flow fields in undular and hydraulic jumps have been acquired with single-camera particle image velocimetry PIV . Three Froude numbers, ranging from 1.4 to 3.0, were studied, and in each case data were collected at numerous streamwise locations. The data from these streamwise locations were subsequently compiled into spatially dense 80,000 grid points “mos...

Investigation of Undular Hydraulic Jump over Smooth Beds

Undular hydraulic jumps are illustrated by a smooth rise of the free surface followed by a train of stationary waves. They are sometimes experienced in natural waterways and rivers. The characteristics of undular hydraulic jumps are studied here. The height, amplitude and the main characteristics of undular jump is depended on the upstream Froude number and aspect ratio. The experiments were do...

Model for polygonal hydraulic jumps.

We propose a phenomenological model for the polygonal hydraulic jumps discovered by Ellegaard and co-workers [Nature (London) 392, 767 (1998); Nonlinearity 12, 1 (1999); Physica B 228, 1 (1996)], based on the known flow structure for the type-II hydraulic jumps with a "roller" (separation eddy) near the free surface in the jump region. The model consists of mass conservation and radial force ba...

Unsteady Turbulence Characteristics in an Undular Bore

When a river mouth has a flat converging shape with a tidal range exceeding 6 to 9 m, the river may experience a tidal bore. A tidal bore is a positive surge, and the aim of the study is to detail the turbulent field beneath an undular bore. New unsteady experiments were conducted in a large channel. Turbulence measurements were performed with high-temporal resolution using side-looking acousti...

Two-dimensional bubble clustering in hydraulic jumps